Inducibility of the Epstein-Barr virus (EBV) cycle and surface marker properties of ebv-negative lymphoma lines and theirin vitro EBV-converted sublines

Abstract

Two EBV‐negative lymphoma lines of human B‐cell origin, BJAB and Ramos, were compared with altogether six of their in vitro EBV‐converted, EBNA‐ and EBV‐DNA‐carrying sublines (four of Ramos and two of BJAB derivation). All converted lines closely resembled the parental line with regard to karyotype and HL‐A and B antigen typing. Induction of EBV antigens (EA and VCA) by P3HR‐1 virus superinfection was either similar in the converted and the negative lines, or somewhat increased in certain converted lines. These findings argue against a simple, virally determined repressor model and emphasize the role of cellular controls in restricting the EBV cycle in virus‐carrying B‐lymphocyte lines of human origin. IUdR inducibility varied in the different converted lines. There was a possible relationship between average number of EBV‐genome equivalents per cell and inducibility. Converted sublines did not differ from the original negative lines with regard to surface immunoglobulin and Fc receptors. There was a dramatic increase in complementconsuming ability, however, following EBV conversion. Among the EBV‐positive lines, there was a linear relationship between complement‐consuming and EBV‐receptor activity, the latter measured by a quantitative absorption test.